The substituted diphenylalkanes have progressed through several stages of evolution over the past 45 years. The first commercially successful example in this class was DDT. Different types of stuctural modifications have resulted in many other series of insecticidal compounds, including a number of other commercial products. Each series of new derivatives developed has also contributed to a greater data base from which structure-activity relationships can be drawn. Steric effects such as size, position, branching, and symmetry among substituents have been demonstrated to be important to the biological activity. Electronic factors, e.g., electronegativity, also exert effects at the site of action, the nerve axon. Lipophilicity is also a parameter that contributes to toxicity of the diphenyl alkanes.
There is obviously a continuing and primary need for new insecticidal compositions widely effective against pests and insects when applied in economically feasible quantities.
Accordingly, this invention has as its primary objective, the development of new insecticides using many of the valuable properties of diphenylalkane insecticides of the past, but still having other certain structural moiety modifications which are designed to make the new derivatives more highly effective from the standpoint of their steric effects upon biological activity, and their electronic factors which affect actions at the site of the nerve axon and finally, which affect their lipophilicity, all designed to significantly enhance the toxicity of the diphenylalkane.
It is another primary objective of the present invention to provide certain diphenylalkane insecticides which can be easily synthesized, which are easy to work with, which have a kill efficiency that is considered good at relatively low levels of usage, and which have an overall significantly improved utility for general insecticidal uses.